Electric generating plant for the drive of vehicles



Oct. 12, 1948. o. SCHLPFER 2,451,242

ELECTRIC GENERATING PLANT FOR THE DRIVE OF VEHICLES 3 Sheets-Sheet lFiled Oct. 2, 1945 uw NN wN BY fm,

@ma MMM MM@ ATTO R N EY O. SCHLPFER oct, 12, 194s.

ELECTRIC GENERATING PLANT FOR THE DRIVE OF VEHICLES Filed 001'.. 2, 19453 Sheets-Sheet 2 O. SCHLPFER Oct. 12, 1948.

ELECTRIC GENERATING PLANT FOR THE DRIVE OF VEHICLES Filed 06t- 2, 1945 3Sheets-Sheet 5 ATTQRNEYS Patented ct. l2, 194g ELECTRIC GENERATING PLANTFOR THE DRIVE OF VEHICLES Oskar Schlapfer, Winterthur, Switzerland,assignor to Sulzer Freres, Societe Anonyme, Winterthur, SwitzerlandApplication Gctober 2, 1945, Serial N0. 619,797 In Switzerland January15, 1945 '7 Claims.

The invention relates to an electric generating plant for the drive ofvehicles with an electric generator driven by an internal-combustionengine and an automatically acting governing device, which adjusts thefuel and the field current in accordance with the speed of theinternal-combustion engine and the electric generator. Such plants areadapted particularly for driving rail vehicles, but may also be used,for instance, on road vehicles and water craft.

In plants of the type mentioned, if the quantity of fuel and thestrength of the eld current of the electric generator are adjustedsimultaneously by the same governor, the drawback arises that theservice points of such a plant, whose governing is in equilibrium, aresituated so unfavourably as regards tractive elfort and the speed of thevehicle, that the full output of the internal combustion engine andelectric generator can only be utilised over quite a small speed range.With this very simple governing, if an astatic characteristic is givenby adopting an auxiliary motor to adjust the field-current regulator,better utilisation of the full output of the internal-combustion engineand electric generator can be obtained. On the other hand, however,hunting will arise in the governing, since the field-current regulatorcan never get into a steady state because of the enforced astaticcharacteristic.

It has also been proposed to adjust the quantity of fuel as well as thefield-current strength by regulators with an astatic characteristic, butto keep the ranges of adjustment separate from each other, so that in aregion of lower load the fuel regulation alone, and in a region ofhigher load the field-current regulation alone would come intooperation. But because of the astatic characteristic of bothregulations, oscillations occur to an even greater degree, since thestabilising action of the fuel regulation is not present duringregulation of the field-current.

According to the invention, it is proposed tO adopt, in electricgenerating plants of the type described, a control device influenced bya speed governor and controlling the fuel and field-current regulatorsin such a way that, in a region of high speeds, a definite position ofthe fuel regulator absolutely corresponds to each position of the speedgovernor, and in a region of l lator in the region of the position formaximum fuel feed, and at least during the greater part of the region ofhigher speeds keep the fieldcurrent regulator in the region of theposition for maximum field-current.

In a third region of lowest speeds, the control device may again controlthe fuel regulator for instance in such a way, that a certain positionof the fuel regulator is definitely allocated to each position of thespeed governor.

The region of higher speeds in which the fuel regulator is influencedand the region of lower speeds in which the field-current regulator isinfluenced, may be directly connected together, or they may be separatedby an intermediate region in which neither the fuel regulator nor thefieldcurrent regulator is influenced. These regions may, however, alsooverlap to a certain extent, and there both the fuel regulator and thefieldcurrent regulator are influenced.

Further an adjusting device may be provided with which the speed regionscan be altered. By means of a further device, for instance, the quantityof fuel may be limited if the control device would adjust to a greaterquantity of fuel when troubles occur, than is admissible with thesupercharging pressure at the moment. Finally a device may also beadopted which, influenced by the starting device particularly in theregion of lower speeds, adjusts to an increased quantity of fuel duringstarting.

The invention is further explained with the help of the drawing.

Fig. l shows as first example of execution an electric generating plantfor driving a rail vehicle in which the regions of fuel regulation andfield-current regulation are directly adjacent to each other.

Figs. .2a-c illustrate different positions of a control lever of theplant according to Fig. 1.

Figs. Sa-c show in the same manner as Fig. 2 the lever of a controldevice in which the speed region of field-current regulation isseparated from the speed region of fuel regulation by a normalintermediate region in which neither of the regulating devices isinfluenced.

Figs. 4a-c illustrate, as Fig. 2,'-the lever of a control device inwhich the speed region of fuel regulation and the speed region offield-current regulation overlap to a certain extent.

The figures marked a in Figs. 2-4 show the positions in which only thefuel regulator is influenced, those marked b show the middle positionbetween the two speed regions, and those marked agora@ 3 the positionsin which only the held-current regulator is influenced.

Fig. 5 shows a control device for an electric generating plant in whichthe field-current regulator is equipped with a retarding device.

Fig. 6 illustrates a control device in which, in addition to the twonormal speed regions of fuel regulation and eld current regulation stilla third speed region is provided beyond the region for field-currentregulation; in' it the fuel regulator is influenced again.

Fig. 7 shows a similar control device as in Fig. 6.

Fig. 8 represents a part of a control device for a supercharged internalcombustion engine.

Fig. 9 shows a device for y,increasing the fuel feed at starting, whichis inuenced by the starting device.

The internal-combustion engine i as shown in Fig. 1 drives an electricgenerator 2 and an exciter 3. The'current from the electric generatingplant is used for driving the traction motors l of a rail vehicle.Between the electric generatorZ and the traction motors d theswitch-gear required for working the vehicle (for instancereversingswitch, over-current relay, etc.) are arranged together in ablock 5. The exciter 3 feeds the field coil 6' of the electric generator2. For regulating th'eY-e'ld-current, the regulating resistance l isprovided which is short-'circuited in the position II)v and has thegreatest resistance inserted in the position Il.

Each working cylinder of the internal combustion engine I has a fuelpump 8. All fuel pumps of the linkage 29.

areV regulated in common by means of linkage 9, d?

When the stop' collarv 36 takes up the position i0, shown on' the scaleassociated with the linkage 9 in Fig.v 1, at the left, the maximumquantity' of fuell is delivered, While, if the-linkage 9 shifts to 311fight, bringing-stop co'iia'r's to the position t, i

no fuel is' delivered. By means of the superchargin'g compressor 5I,which may be driven for instance by` an eXhaustl gas turbine not shown,the combustion air is led to the internal-combustion engine Iv atanincreased pressure.

For adjustingV thefuel regulating linkage 9 and the' field-currentregulator l, a speed governor I'2' constructed as centrifugal governoris used. The sleeve I3'y of this governor experiences through theIspring Ill a loading which is adjustable by meanshof the hand-wheelV I5.-To the sleeve I3' the regulating lever' I6 is jointed, which is jointedat the vopposite end to the piston rodsv Il of the s'er'voin'o'torpiston t8I `and in the middle to the rod I 9 of the controlvalve 2?. Tothe piston rods Il of the servomotor piston I8 is also jointed thecontrol lever 2l', which makes it possible on the one hand to influencethe linkage 22, 23, 9` 0f. the fuel-regulator and on the Yother hand thelinkage 24, 25 of the field-current regulator l.

To the spindle 2B, by means of which the pressure on the sleeve of thespeed governor I2 can badjusted, a lever 28 is jointed by means of asleeve 2l and adjusts the middlepivot 30 of the regulating lever 23'through a linkage 2S. y

By means of the control device, Vthe fuel regulator 9 andthefield-curr'ent regulator 'l are contrelled through the' speedgovernor I2, in accordance with the speed of the internal-combustionengine I and' of the electric generatorZ', in such a way that in aregion of higher speeds a certain position'- of, thefuelregulator isdefinitely allocatedV to each position of the speed governor, and inaregion' of lower speeds a certain position of the field-currentregulator is definitely allocated' to each position of the speedgovernor.

" feed governor does not take place a each osition of the speed governorI2 and themsleeve Ir, a certain position of the servoinotor piston isdefinitely allocated when the plant is 1n a steady state. The dottedlines Ia and ISb show the extreme limiting positions of thel lever I5 inthe steady state of the regulating device, whilst the dotted lines Icand IGd shows the exti eine limiting positions while the regulationisbeing adjusted. In this way also for each position o the speedgovernor I2 there is an absolutely dennite position of the control leverZI in the steady state. This lever 2|, in a region between the positionEla, and the limiting position 2th,'1niiuences the linkage 22, 23, 9 ofthe fuel regulator and m the region between the position 2 la the otherlimiting position 2Ic influences the linkage 2, 25 of the field-currentregulator l.

In the position of the control device shown in Fig. 1, the fuelregulator 9 isin the region for adjusting to the greatest quantity cffuel. lIn this case;v the spring plate of the linkage 221s. held to thestop 32 by the Spring I. The position of the pivot 3B of the lever 23 isgiven by the position In this way, the position o; r 23 is determinedThe fuel regulator tlrgnltnds in a position which gives the greatestpossible quantity of fuel for the speed regioi; ai; justed by thespindle 2t; An influesnlcrr gs the lever 2| remains in the regionbetween the posind`2Ic. A twllsieg Ifiletti-current regulator l is in .aposition between the positions Il and ID. In this case the linkage 24 isbrought into contact with the leve;` 2l by means of the spring 33.l Thetwo stops 3 and 34 are set in such a way that the spring platesconnected to the linkages 22 and 2li come to lie on them exactly whenthe lever 2| reaches the position 21a. If the fuel regulator isinfluenced the region of higher speeds, the field-current regulatorremains unchanged in the region ofY osition for the strongestfield-current.

thielvth the help of the adjusting device I5, 26 the speed regions can'be altered, whereby on the one hand only the fuel regulator and on theother hand only the field-current regulator is mtlvnitidthe help of thehandwheel I5 and the spindle 2B, the spring I4 is given a greatertensioni, an increased speed of the internal-combustion engine isnecessary in order to keeptlie lever Iiiv in the positions between thelimiting positions Ildl and Ib. At the same time, 1the'le- Ver 2'8 ispushed in a direction towards tne limiting position 28a. The lever 2tthen takes up itsv position 2la as compared with the foiinei setting,only at a higher speed'. At the same time, with the help of the linkage29, the pivot 30 of the lever 23' is' moved to the left, so that in thismiddle position" an increased quantity of fuel is adjusted. The' speedregions are thereby moved into regions of higher speeds. Within thesenew speed regions, the fuel and the field current regulators are againinfluenced in such a way, that in the region of higher speeds a certainposition of the fuel regulator is ldenitely allocated toV each positionof the speed governoi and` in theV region of lower speeds acertainposition of the nein-current regulator is -dsnmteiy allocated toeach position of the speed governor.

if with the help of the adjusting esvioo i5, 2e the load on the springIiis decreased and uis lever 28 is moved towards the limiting position2353 h'e pOStoIls of" the leverv I8 lying between' the limitingpositions Ia and Iiib are adjusted at the lower speed. The position 2 Iaof the lever 2| will thereby be maintained between the two speed regionsalso at a lower speed than in the position shown in Fig. 1. Through thelinkage 29 the pivot 39 of the lever 23 is moved towards the right, sothat a smaller quantity of fuel is adjusted. The two regions aretherefore moved into regions of lower speeds. Thereby in the region ofhigher speeds a certain position of the fuel regulator is definitelyallocated to each position of the speed governor and in the region oflower speeds a certain position of the eldcurrent regulator isdefinitely allocated to each position of the speed governor.

The position of the fuel pump regulator 9 cannot come into the position0. For this purpose, a spring member 35 is provided in the linkage 9 andis pressed together after reaching the 0 position of the fuel regulator,if the lever 23 should be moved still further. The El position of thefuel regulating linkage 9 is determined by a collar 36 and the stop 31.

The device 38, which cornes into action as a supercharging safetydevice, prevents thermal loading of the supercharged internal-combustionengine if, in consequence of a disturbance or outside the steady state,the supercharging pressure should be higher than what would correspondto the quantity of fuel set by the speed governor I2. If thesupercharging pressure is higher than is necessary for the exactquantity of fuel adjusted, the bellows 39 and the spring 49 are pressedso far together, that the stop 4I is raised from the stop `42. But, ifthe supercharging pressure is too low, the spring 40 presses the fuelregulating linkage 9 over the stop 4I, 42 to the right. The lever 23 isthen turned counterclockwise, whereby the linkage 22 can be removed fromthe lever 2 I.

Through the reduction in the quantity of fuel, there is less output fromthe plant. The speed falls and the sleeve I3 of the governor I2 moves tothe left. Then also the servomotor piston I8 and the lever 2| movetowards the right, so that a part of the regulating resistance 1 isinserted. The load of the internal-combustion engine is therebydecreased and with the diminished load a new steady state is reached ata lower speed.

Fig. 2 shows the control lever 2| of Fig. l in various positions. In thepositions according to Fig. 2a, in a region of higher speeds only thelinkage 2.2 of the fuel regulator is influence-d, whilst the springplate of the linkage 24 for the held-current regulator lies on the stop34. Fig. 2b shows the position 2|a of the lever 2|. In this position thespring plate of the linkage 22 for the fuel regulation and also thespring plate of the linkage 24 for the field-current regulation lie onthe stops 32 and 34. Here then the linkage 22 and also the spring plateof the linkage 24 just touch the lever 2|, so that between the linkageand the lever there is no clearance. In the position 2c only the linkage24 of the eldcurrent regulator is influenced in a region of lov/- erspeeds, whilst the linkage 22 of the fuel regulator lies with its springplate on stop 32.

Fig. 3 shows the form of control device in which between the two speedregions a small intermediate region is inserted, in which neither thefuel regulator nor the field-current regulator is influenced. Thepositions according to Figs. 3a and 3c correspond to the positionsaccording to Figs. 2a and 2c, in which on the one hand only the fuelregulator is influenced, and in the other hand only the field-currentregulator. From Fig. 3b it can be seen that between the two positions ofthe linkages .22 and 24, in which their spring plates rest on the stops32 and 34, an intermediate region a: eXists in which the lever 2| doesnot touch either of the two linkages.

In the form of -control device according to Fig. 4, the two speedregions, in which the fuel regulator on the one hand and thefield-current regulator on the other hand are infiuenced, overlap neartheir ends. The positions 4a and 4c again correspond to the positions 2aand 2c. In the middle position according to Fig. 4b, however, neitherthe spring plate of the linkage 22 nor the spring plate of the linkage24 is in contact with the stops 32 and 34 respectively. Here, both thequantity of fuel and also the strength of the field-current will Abechanged within a certain limited region.

In the control device shown in Fig. 5, the fuel regulator 9 isinfluenced in the same way as in the plant according to Fig. l. On theother hand, the field-current regulator 'I is only influenced as it isin the plant according to Fig. l, when the strength of the field-currentis weakened by displacement in the direction from the position I0towards the position il. When increasing the field-current strength bydisplacing in the opposite direction, the regulating motion is retarded,so that the time taken to adjust is lengthened. For this purpose, abraking piston 43 is connected to the linkage 24. When the contact lever25 on the field-current regulator 1 moves in the direction from positionIG towards position Il, a gas or liquid with low resistance is drawn inthrough the valve 44. With movement in the contrary direction, this gasor liquid is pressed out with increased resistance through the throttleposition 45. When the linkage 24 is moving to the left under theinfluence of the brake, it may be temporarily raised from the lever 2|.It will, however, be led closer to the lever 2| by the vspring 33, untilit comes to rest on it or reaches the stop 34 by means of the plate ofspring 33.

The control device shown in Fig. 6 sets the fuel regulator again in athird region of lowest speeds, so that a, certain position of the fuelregulator is allocated to each position of the speed governor. Thefield-current regulator 1 has beyond the positio-n 9 a further region inwhich a constant diminished field-current is set, corresponding to theposition 0. In this region, the linkage 22 is drawn further to theright, by means of a slot 46 and the lever 2|, so that the quantity offuel is sti further increased.

Here the plate of the spring 3|, which at first rested on a movable stop32, is pressed against the `stronger spring 41. The spring 41 pressesthe movable stop 32 into the rst two speed regions against the fixedstop 43. The spring 13| alone cannot raise the movable stop 38 from theXed stop 48 of the spring 41. Only when the slot 46 lies on the pin ofthe lever 2|, can it be raised and thereby increase further the quantityof fuel. Since each position of the lever 2| is allocated to a certainposition of the speed governor I2, in the new third speed region acertain position of the fuel regulator 9 will also correspond to eachposition of the speed governor I2.

The spring member 35 acts in both directions. The spring 49 is pressedtogether when the supercharging safety device comes into action, whilstthe spring 5l) is pressed together when the fuel regulator 9 reaches thestop in the position for 0 fuel feed, but the lever '23 is displacedfurther and displace's' the bell-crank lever 52.

7. tire' ssei'f' afrduetionpf'th quantity-0f fuel'.

The control device illusti"atedA in Fig. 7'a'o'tsV irl the two firstVspeed-regions like: the control device according to Fgf. Between thelever 2|y and the fuel regulating linkage 9,'- a connection, effectedonly in one direction, acts in the third speed' region. The springmember 35 therefore requires to be arranged to Vact only in onedirection. On the'control lever 2|4 an arm 5l' is also fixed, whichdisplaces Vthe two-armed lever 52'f after the first two speedregionsliave'` been passed through'. In this way, the movable stop 32lisl moved towards'the rightso that the' spring plate fixed on'thelinkage 22 can' follow it; Thereby the lever 23 is drawn after' and thequantity of fuelv further'increased. When the fuel regulating linkage"Scomes into thev regulating position l" for the greatest quantity offuel, it remains simply standing at its top, whilstth'e movable stop 32can'rnove still further towards the right.

In th'e'c'ontrol device illustrated' in Fig. 9, where some partsV have.been omitted', the'supercharging safety' device 38 acts on the'le'ver`23. In addition to' the' spring member 35m the fuel regulating linkage9, aspring member 53 is also fitted in the linkage' 2`9".Ifthe'sup'ercharging pressureV is less than' the' pressure correspondingto the quantity of fuel to' which the device' is adjusted, theloellows39 extend sov greatly under" the pressure' of the spring 40, that, withthe help of the linkage' 54 and' the'fork' 55the pivot 30 of the lever213 is pushed'towards the right. In thisway', the fuel regulatinglinkagev is brought'into a position for asrnaller quantity of fuel.

The device shown in' Fig. 9 serves to increase the quantity' of fuelduring starting. The plate of the springl rests again-st a; movable stop32' whose position is' determined' by the piston 56" through thebell-crank lever 52. This piston is influenced' on the one hand by thespring 51 and onth'e other hand by a pressure medium flowing in throughtheV pipe 58. A Contact 59 closes an electric" circuit" by means of thecoil ''du'ring starting so that the valve 6l is 'raised'. Therebypressure medium flows into'the cylinder space of the piston 56,. pressesthe piston downwards In this way, the stop 32 is moved towards theright'and consequently the fuel quantity is adjusted to a greateramount' for starting. As soon as contact 59 reaches'the'open positionafter starting, the electric circuit is` broken by the coil 60 and thenthe valve BI can come into the closed position. The piston'56' isthen'raised by the pressure of the spring 57, and the stop 32 is againmoved into its'norrnal position.' Liquid pumps, for instance, could alsobe'used as speed-governors.

14 claim:

1. An electric generating plant forvehicle propulsion including' aninternal combustion engine, an electric generator driven by said engine,andan'automatic regulating` device that includesv aspee'd governordriven by said engine, acontrol device inlluenced. by said governor', afuel regulator controlling' the admission" of fuel to said' engine andinfluenced by said control device in the region of higher engine speedsonly to admita definite amount of fuel for each speed in that region, afield 'current regulatorcontrolling the field current of said generatorand influenced by` said control device in the region of lower enginespeeds only' to provide a definite i'1leld'ff'zurl#A rent for each speedin thatregion", and output adjusting means tha-t include a device forsetting said governor to the desired speed and means vfor regulating therange ofV inuence of said control device over' said fuel regulator, saidgovernorsetting-device and said influe'nce-range-regulating means beingadjusted in common by Vmanipulation ofv said output adjusting means.

2. An electric generating plant according to claim 1 in which anadditional control device influenced by the governor influences the fuelregu'- lator in the region of lowest speeds only.

3. An electric generatingA plant according to' claim 1 in which theengine is provided with supercharging means, asafetyl governing deviceinfluenced by the supercharging pressure, andan additional means forregulating the range of in-` fluence ofthe control device over thefuelregue lator whereby the amount of fuel admitted to the engine can neverexceed an amount appropriate to the existing supercharging pressure. y

4. An electric generating plant according to claim 1 in which theIengine includes -a starting device and theY fuel regulator is providedWith an additional control device influenced'b'y the start' ing devicewhereby an increased amount of fuel is admitted to the engine during thestarting process independent of the' influence of the speed governor.

5. An electric generating plant according to claim 1, characterized inthat the region of higher speeds, in which the fuel regulator isinfluenced, andthe region of lower speeds, in which the fieldcurrentregulator is influenced, are directly adjacent to each other.

6. An electric generating plant according tol claim 1, characterized inthat the region of higher' speeds, in which the fuel regulator isinfluenced, and the region of lower speeds, in which the fieldcurrentVregulator is influenced, are separated from each other by anintermediateV region in which neither the fuel regulator nor theeldcurrent regulator is influenced.

7. An electric generatingplan't as claimed in claim l, characterized inthat the region of higher speeds, in which the fuel regulator isinfluenced, and the region of lower'speeds, in which the fieldcurrentregulator is influenced, overlap to a certain extent, and there thevfuel regulator and also the field-current regulator are influenced.

OSKAR SCHLPFER.

REFERENCES CITED The following'references are of record inthe* flleoft-his patent:

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